Many vaccines rely on the ‘predict and produce’ approach. For example, influenza vaccines are generated based on the hemagglutinin and neuraminidase sequences of virus strains that are the most likely to spread across the globe during flu season. However, changes in a circulating virus or the emergence of a pandemic strain with major changes in its glycoproteins would render such vaccines ineffective. In addition, the current egg-based influenza vaccine manufacturing technology depends on the ability of the flu strain to replicate in eggs and takes at least six months to manufacture sufficient doses for the seasonal vaccination campaign.
The production capacity for current vaccines is estimated to be lower than what is required to vaccinate the present global population. Furthermore, vaccines, such as DNA vaccines, have long suffered from inefficient transfection of host cells via syringe-based delivery. Accordingly, drawbacks associated with a limited means for increasing vaccine dose production, as well as lack of new technologies for increasing vaccine transfection, have raised concerns among health-care professionals.
It is not known how to increase DNA vaccine transfection. Further, it is not known how to design antigenic epitopes or vaccines for antigen presentation so as to maximize the induction of an appropriate immune-response. Faster and simplified vaccine manufacturing technologies are needed for influenza and non-influenza-related vaccine strategies to be viable solutions in the event of future pandemics. Accordingly, there is a need for better methods of antigen selection and design for antigen-based vaccines, which can efficiently transfect host target cells and are effective against various diseases.